The present invention relates generally to computer devices, and more particularly computer devices arranged to receive handwritten input.
Contemporary computing devices allow users to enter handwritten words (e.g., in cursive handwriting and/or printed handwritten characters) and symbols (e.g., a character in Far East languages). The words and symbols can be used as is, e.g., to function as readable notes and so forth, or can be converted to text for more conventional computer uses. To convert to text, for example, as a user writes strokes representing words or other symbols onto a touch-sensitive computer screen or the like, a handwriting recognizer (e.g., trained with millions of samples, employing a dictionary, context and other rules) is able to convert the handwriting data into dictionary words or symbols. In this manner, users are able to enter textual data without necessarily needing a keyboard.
However, contemporary recognizers are too processor-intensive to use continuously, particularly with small hand-held (pocket-sized) personal computers. Instead, the devices are configured such that users can request recognition when desired, or such that the recognizer operates only in the background so that the users do not have to wait for recognition on a word-by-word basis. Moreover, some recognizers are configured to use the context of surrounding words or symbols to help determine other words or symbols, and thus waiting to recognize groups of words often provides more accurate recognition.
At the same time, however, the user may wish to edit words and symbols before they have been recognized, e.g., delete a word, insert a word between two others, format a word, move words around, and so forth, such as by cutting and pasting. Also, the system needs to know when to wrap handwritten data to the next line, and needs to maintain this information as the user zooms the display in and out. As such, some relatively lightweight, initial ink processing is performed to parse the input data into various segments, without involving the recognizer. This initial processing may be orders of magnitude faster than full recognition, but has problems, however, in that because it only looks for limited characteristics via some fuzzy rules, the distinct segments initially determined may not actually correspond to the distinct words or symbols that the user intended. Thus, as a user edits words and zooms in and out, the user may undesirably find that what was intended to be one word is treated as two, two words treated as one, and so forth.
Briefly, the present invention provides a method and system that corrects for parser segmentation errors by sending an entire line of ink to a recognizer, and then comparing, on a word-by-word basis, the initial segmentation guesses of the parser with the more-thoroughly recognized segmentation results of the handwriting recognition engine. In the correction process, the ink words are efficiently adjusted with relatively little data manipulation. More particularly, the recognizer is fed a series of strokes on a line, in order, from which the recognizer returns its segmentation information. For ink word breaks that are the same between the ink parsing and the recognizer for any given set of data, the existing ink word is unchanged. For ink words that are recognized differently, a new ink word is created and the handwriting (including stroke) data of the parser""s ink word is manipulated to create a new ink processor word (or words) to match the recognizer output.
The present invention thus retains the desirability of rapidly grouping sets of strokes into segmented ink word units as they are written, without first requiring complete recognition, for example for word processing (editing and zooming) purposes, and so forth. However, once recognition is performed, the segmentation performed by the lightweight parser, which is generally not as accurate as the segmentation performed by the recognizer, is efficiently and flexibly corrected by a data manipulation process to match the recognizer""s output.
Other advantages will become apparent from the following detailed description when taken in conjunction with the drawings, in which: